The present invention relates to a wiper arm of an arrangement for wiping a vehicle window. More particularly, it relates to a wiper arm for transmission movement from drive means to a wiping element for cleaning a vehicle window. Wiper arms of wiping arrangements of the above-mentioned general type are known in the art. A known wiper arm has a cover which is secured to a structural member for holding a tension spring in longitudinal direction and is undetachably connected with the same by bent tongues of an arm body member. In order to arrest a wiper rod, the cover is provided with an adjusting screw which is screwed against the wiper rod and requires a tool for its adjustment. A safety screw is further required which prevents unintentional loss of the adjustment screw and thereby prevents unintentional changes of the length of the wiper arm. The cover must also have such a thickness in the region of the threaded bore for the adjustment screw that the pressure force of the screw will be taken up from the cover without damaging the thread of a nut.